Intermediate age related macular degeneration - noninvasive multimodal analysis and longitudinal study

Age-related Macular Degeneration (AMD) is an important cause of irreversible visual impairment, secondary to degenerative macular disorder. AMD can compromise central vision, essential for reading and for recognizing small details. Currently we recognize three stages in AMD: early, intermediate and late stage. Early AMD is characterized by the presence of medium (≥63μm and ≤125μm) drusen with no associated pigmentary abnormalities and intermediate AMD (iAMD) is characterized by the presence of large (>125μm) drusen associated or not with pigmentary abnormalities. Advanced or late AMD can be atrophic or neovascular, with death of photoreceptors associated or not with macular neovascularization. Intermediate stage is a common pathway to more advanced forms of the disease and has, recently, been arousing special interest as a field of AMD investigation. Althought some progress is being made towards a treatment for atrophic AMD no subsequent visual improvement can yet be obtained. Early and intermediate AMD stages have no preventive effective treatment besides general recommendations as eating healthfully, taking vitamin supplements, and not smoking. On the other hand, anti-vascular endothelial growth factor (anti-VEGF) therapies with repeated intravitreal administrations are a proven therapeutic option to control exudative disease. AMD pathophysiology has some known factors (age, genetics, smoke and nutrition) and some others are still under debate. There is a documented genetic background with genes encoding complement system, high-density lipoprotein metabolism, extracellular matrix remodeling, angiogenesis and cell survival. High risk genetic variants linked to AMD are found in the genes related complement system proteins (complement factor I, complement C2, C3, C9, and CFH). Other possible implicating factors identified as predictors for AMD development are human high-temperature requirement A-1 (HTRA1) and Age-related Maculopathy Susceptibility 2 (ARMS2) as well as other rare genetic variants. It seems ...